title: The safety and efficacy of thalamic deep brain stimulation in essential tremor: 10 years and beyond.
abstract: BACKGROUND
  Deep brain stimulation (DBS) has proven to be a safe and effective therapy for refractory essential tremor, but information regarding long-term outcomes is lacking.
  
  
  OBJECTIVE
  We aimed to assess the long-term safety and efficacy of DBS in patients with essential tremor.
  
  
  METHODS
  Patients treated with DBS for essential tremor for at least 8 years were evaluated in the 'on' and 'off' state using the Fahn-Tolosa-Marin tremor rating scale, and their medical records were reviewed to assess complications related to this therapy.
  
  
  RESULTS
  We studied 13 patients (7 men): median age at evaluation 79 years (range 47-88), median age at electrode implantation 68 years (range 37-78) and mean time since electrode implantation 132.54±15.3 months (range 114-164). The difference between the 'off' and 'on' state on the motor items of the tremor rating scale was 41.9% (58.62 vs. 34.08, p<0.001) in the non-blinded and 37.2% (56.07 vs. 35.23, p<0.001) in the blinded rating. DBS provided a functional improvement of 31.7% in the 'on' state (15.07 vs. 22.07, p<0.001). A total non-blinded improvement in the tremor rating scale of 39% was observed in the 'on' state (49.15 vs. 80.69, p<0.001). Dysarthria and disequilibrium were common in patients with bilateral stimulation. A DBS-related surgery (electrode revision or internal pulse generator exchange) was necessary on average every 47.9 months to continue with the DBS therapy.
  
  
  CONCLUSIONS
  Thalamic DBS is a safe and effective therapy in patients with essential tremor followed for up to 13 years.
authors.affiliation: Department of Neurology, Parkinson's Disease Center and Movement Disorders Clinic, Baylor College of Medicine, , Houston, Texas, USA.
authors.forename: José Fidel
authors.initials: JF
authors.lastname: Baizabal-Carvallo
authors.forename: Melissa N
authors.initials: MN
authors.lastname: Kagnoff
authors.forename: Joohi
authors.initials: J
authors.lastname: Jimenez-Shahed
authors.forename: Robert
authors.initials: R
authors.lastname: Fekete
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D046690:Deep Brain Stimulation; D004401:Dysarthria / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D020329:Essential Tremor / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D020233:Gait Disorders, Neurologic / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D013788:Thalamus; D013997:Time Factors; D016896:Treatment Outcome
keywords: ELECTRICAL STIMULATION; TREMOR